Endocrine Abstracts

Graves’ disease (GD) is the most common cause of hyperthyroidism with incidence rates of 20-50 cases per 100,000. Genetic predisposition and environmental factors are known to play a role in its pathogenesis. After perceiving an increase in the number of cases presenting to our thyroid clinic we confirmed a rise in the incidence of GD in North West Wales since the start of the COVID-19 pandemic. The annual incidence of GD was calculated using the number of positive thyroid stimulating immunoglobulins (TSI) results with associated thyrotoxicosis. 40 new cases of GD were diagnosed in 2019, 48 in 2020 and 64 in 2021 i.e. a 60% increase in 2021 from the pre-pandemic level in 2019. The number of relapses of known cases was similar with 17 in 2019, 19 in 2020 and 20 in 2021. There was no significant difference in mean TSI levels (8.6 IU/l in 2019, 11.7 IU/l in 2020 and 12.1 IU/l in 2021) or severity of the thyrotoxicosis (mean fT4 levels 37.1 pmo/l in 2019, 42.2 pmo/l in 2020 and 39.6 pmo/l in 2021). Figures for the first 6 months of 2022 suggest a decrease in the incidence rate with 22 new cases (representing a 50% decrease compared to the same period in 2021) and 15 relapses of GD. Cases of GD post-COVID infection and vaccination have been reported in the literature. Initial analysis of our data suggests the possibility of a COVID vaccination effect in the increase. The incidence of GD for the first half of 2022 suggests a return to the pre-pandemic rate.